1. Field of the Invention
The present invention relates generally to a process and structure for disposing of or storing hazardous waste materials above ground and isolating the hazardous waste material from the environment, specifically including surface and ground water.
2. Description of the Prior Art
There are literally millions of tons of hazardous waste materials that have been generated through numerous governmental, industrial, and private operations. Much of that generated waste is now held in open storage pits or containers. Today, tremendous quantities of hazardous wastes are continuously being generated. These hazardous waste contain various contaminants, and unless the wastes are properly isolated or disposed of, the contaminants in the waste can leach into the surrounding environment, earth and ground water and thereby damage the environment and pose significant risks to human life.
Hazardous wastes often include significant quantities of commercially desirable and expensive materials, such as mercury, zinc, chromium, magnesium and copper, to name a few. Although it is now often difficult or impossible to economically recover such materials from wastes, future advancements in technology and the probable rising costs for those materials might make their recovery an economic reality in the future. Under presently available hazardous waste disposal techniques, these materials are either incinerated and lost forever, or are buried in such a manner that it is either impossible or extremely difficult and costly to gain later access to the waste and materials.
Because of the detrimental nature of hazardous waste, a generator of the waste must dispose of or properly isolate the waste in some manner. If a waste-generator fails to take appropriate action, it will subject itself to a high risk of fines and potential lawsuits. Perhaps more importantly when the inevitable leaching of contaminants in unisolated hazardous waste occurs, the generator will then have to take direct remedial action. This remedial action in almost all cases will be more expensive than the cost of initially isolating or disposing of the waste. Furthermore, a generator failing to properly dispose of hazardous waste may be liable for the resultant damages to property and persons.
Despite the relative importance of waste disposal to industry and the community, the presently available options to dispose of hazardous waste are limited. Today, hazardous waste must be disposed of in compliance with existing governmental statutes and regulations. For the millions of tons of hazardous wastes that already exist, the available options are severly limited. Under current EPA regulations, existing hazardous waste can be disposed of only through land treatment, such as deep wells and landfills, or technical treatment, such as incineration, chemical treatment, or biological treatment.
Today hazardous waste materials are usually either disposed of through an incineration process or contained or isolated in a government-permitted ground cavity. The disposal of hazardous waste through incineration is an expensive process. The hazardous waste first must be processed and transported to an incinerator. The cost of transporting tons of waste by special containers or vehicles can be expensive. Moreover, the transportation of hazardous waste from the generator's premises to an incinerator may increase the risk of contamination since contamination can occur during the initial processing and subsequent transportation of the waste. Even when the waste reaches the incineration site, the cost of actual disposal is expensive because the incineration process itself has large capital, energy and process material costs.
Because of the high costs of technical treatment of wastes, land treatment is often the method chosen to dispose of hazardous wastes. By regulation, hazardous wastes can only be land treated at government-permitted treatment sites. Most approved land treatment sites are underground landfills, and these sites are limited both in number and in geographic location. Therefore, most existing hazardous waste must be transported to approved waste sites. Again, the cost of transporting wastes to approved landfills can be expensive.
Below ground land disposal, if improperly performed, may be unreliable, and if failure occurs, the resultant contamination may be difficult to control. Below ground disposal systems, whether they be land farms, landfills, or deep wells, are located in the sometimes unpredictable medium of earth and ground water. If surface water reaches the hazardous waste, leachate over time may seep into and contaminate the surrounding earth and ground water. Once contamination of the surrounding earth occurs, the contamination may be difficult to control. If ground water is contaminated, expensive remedial procedures will be required to control or isolate the contamination itself.
It is necessary to accurately monitor any leakage of water to or from hazardous waste materials held in below ground containments, and monitoring systems to accomplish this are complex, expensive and not always reliable. Therefore, existing monitoring systems for below ground landfills often can only sense when contamination actually occurs. They seldom warn of a potential problem which can be corrected before actual contamination takes place.
As it is evident from the foregoing discussion, conventional land disposal methods for processing hazardous wastes can pose hazards to the environment or public health and may require significant monitoring, corrective and remedial actions.